Question

我在mySQL中使用这行代码：

select sum(amount) as 'October_Amount' from table
where month(date)=month(now());

我希望在“Month_Amount”字符串中获取当前月份（例如“October_Amount”）。我试过这个：

select sum(amount) as monthname(curdate()) from table
where month(date)=month(now());

但它不起作用。 (monthname(now()))或(monthname(curdate()))是字符串，因此它应该有效。我尝试了很多版本，没有找到任何建议。

Answer 1

试试这个：

select sum(amount), monthname(curdate()) from table
where month(date)=month(now());

或者这个：

select sum(amount), CONCAT('AMOUNT_', monthname(curdate())) from table
where month(date)=month(now());

Answer 2

select  CONCAT(sum(amount), '_', month(now())) from table where
month(date)=month(now());

Answer 3

如果您想使用列名动态，可以像这样使用PREPARED STATEMENTS

SET @date = DATE_FORMAT( CURDATE(),'%M');
SET @query = CONCAT('SELECT SUM(amount) AS "', @date, '_Amount" FROM table where MONTH(date) = MONTH(NOW())');
PREPARE dynamic_statement FROM @query;
EXECUTE dynamic_statement;
DEALLOCATE PREPARE dynamic_statement;

mySQL：从表中选择“variable”作为“variable2”

3 个答案: